thule's accessories will fit a pretty hefty rectangular barwith the long bolts that thules accessories come with you can mount a thule saddle on a 2 inch crossbar that is about 3 to 3 1/2 inches widewhat are you using for the crossbar?

I ended up fabbing up some mounts for my truck ( '05 Envoy XUV - no one makes anything for its rooftop mounting system) and bolting on some Thule square bars, which aren't square at all. Then I added 2 sets of Hullavators and was good to go ...